The Firing System of the Municipal Waste Incinerator Made by EVT
Jun Wang, Xiong-Juan Shu and Zhi-Hang Chen (University of Shanghai for Science and Technology, Shanghai 200093)
With the rapid growth of urban population and improvement of living standards in China, the disposal of municipal refuse is becoming an increasingly serious environmental and economic problem. The solid waste incinerator, which has been used extensively in western developed countries, has proved to be adequate and very effective for the disposal of municipal waste.In western developed countries, municipal waste incinerators have been in production and use for several decades. They tend to be very large dealing with, possibly, several thousand tons of refuse every day. By comparison, the Chinese manufacturers are getting a start in the production of municipal waste incinerators. Tremendous gaps need to be filled in between the inland and foreign units in respects of technological innovation, design and manufacture. It is thus of importance for the inland manufacturers to learn the status quo of the development, design, manufacturing technologies and application of municipal waste incinerators in developed countries.In this paper, the municipal waste incinerator, particularly its firing system, is introduced which is designed and manufactured by EVT Energie- und Verfahrenstechnik, GEC ALSTHOM, Koln. In this incinerator system are included the refuse-fuel supply system, the inclined reciprocating grate, the furnace, the slag-removal system, the combustion-intensity control system, the combustion-air supply system, the ignition and supplementary firing, the steam generator, refractory liners, the dust-removal equipment, and the flue-gas recirculation system etc. Using a slightly inclined travelling grate, the solid refuse fuel can be uniformly and continuously transported onto the reciprocating grate, where the combustion of the refuse takes place. When fed onto travelling grate, the heat value of the refuse can be determined qualitatively using a pyrometer. The rolling speed of the grate is thus able to be controlled according to the measured heat value. The control of the combustion intensity can guarantee a relatively high combustion quality and maintain the given capacities of the incinerator and the steam generator.